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`IPR2015-00762 - EXHIBIT 1005
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`Zhongshan Broad Ocean Motor Co., Ltd., Petitioner
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`Nidec Motor Corporation, Patent Owner
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`CLAIMS
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`1. A method for controlling a permanent magnet synchronous motor, for performing
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`vector control on the permanent magnet synchronous motor in a sine wave driving mode,
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`comprising:
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`an induced voltage detecting process, for detecting an induced voltage generated in the
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`permanent magnet synchronous motor; and
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`a working state detecting process, for detecting the working state of the permanent
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`magnet synchronous motor based on the detected induced voltage.
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`2. The method for controlling the permanent magnet synchronous motor according to
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`claim 1, comprising:
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`a start processing process, used for performing start processing to start the permanent
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`magnet synchronous motor under the condition that the permanent magnet synchronous
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`motor is stopped or is being stopped in the working state detecting process.
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`3. The method for controlling the permanent magnet synchronous motor according to
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`claim 2, characterized in that
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`the working state detecting process comprises a revolution detecting process,
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`for
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`detecting revolutions of the permanent magnet synchronous motor,
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`the condition that the permanent magnet synchronous motor is stopped or is being
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`stopped is a condition that
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`the detected revolutions are iess than the stipulated
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`revolutions.
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`4. The method for controlling the permanent magnet synchronous motor according to
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`claim 1., characterized in that
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`the working state detecting process comprises the revolution detecting process, for
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`detecting the revolutions of the permanent magnet synchronous motor, comprising:
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`a stop processing process, enabling the permanent magnet synchronous motor to stop
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`revolving under the condition that the detected revolutions are more than the stipulated
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`2
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`revoiutions; and
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`a start processing process, used for starting the permanent magnet synchronous motor
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`which has stopped revolving in the stop processing process.
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`5. The method for controlling the permanent magnet synchronous motor according to
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`claim 2 or 4, characterized in that
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`the start processing process comprises an initiai position transfer process, for transferring
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`a rotor to a stipulated angle range of a higher acquiring probability of a positive torque
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`enabling the rotor to rotate in a positive revolving direction; and
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`an initial drive control process, used for performing drive control under the condition that
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`the position of the rotor is within the stipulated angle range to drive the rotor towards the
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`positive revolving direction.
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`6. A device for controlling a permanent magnet synchronous motor, used for performing
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`vector controi on the permanent magnet synchronous motor in a sine wave driving mode,
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`comprising:
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`an induced voitage detecting part, uscd for detecting an induced voltage generated in the
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`permanent magnet synchronous motor; and
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`a working state detecting part, used for detecting the working state of the permanent
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`magnet synchronous motor based on the detected induced voltage.
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`7. The device for controlling the permanent magnet synchronous motor according to
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`claim 6, characterized in that
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`the working state detecting part comprises a start processing part, used for performing
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`start processing to start the permanent magnet synchronous motor under the condition
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`that the permanent magnet synchronous motor is stopped or is being stopped as detected
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`by the working state detecting part.
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`8. The device for controlling the permanent magnet synchronous motor according to
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`claim 7, characterized in that
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`the working state detecting part comprises a revolution detecting part for detecting
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`3
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`revolutions of the permanent magnet synchronous motor,
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`the condition that the permanent magnet synchronous motor is stopped or is being
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`stopped is a condition that
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`the detected revoiutions are less than the stipulated
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`revolutions.
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`9. The device for controiling the permanent magnet synchronous motor according to
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`claim 6; characterized in that
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`the working state detecting part comprises the revolution detecting part, for detecting the
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`revolutions of the permanent magnet synchronous motor;
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`the controlling device comprises a stop processing part, enabling the permanent magnet
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`synchronous motor to stop revolving under the condition that the detected revolutions are
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`more than the stipulated revolutions; and
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`a start processing part, used for starting the permanent magnet synchronous motor which
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`has stopped revolving through the stop processing part.
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`10. The device for controlling the permanent magnet synchronous motor according to
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`claim 7 or 9, characterized in that
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`the start processing part comprises an initiai position transfer part, for transferring a rotor
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`to a stipulated angle range of a higher acquiring probability of a positive torque enabling
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`the rotor to rotate in a positive revolving direction; and
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`an initial drive control part, used for performing drive control under the condition that the
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`position of the rotor is within the stipulated angle range to drive the rotor towards the
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`positive revolving direction.
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`11. An air conditioning device comprises an indoor unit and an outdoor unit,
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`characterized by also comprising:
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`a permanent magnet synchronous motor, used for driving a fan arranged in at least one of
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`the indoor unit and the outdoor unit;
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`an induced voltage detecting part, used for detecting an induced voltage generated in the
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`permanent magnet synchronous motor; and
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`a working state detecting part, used for detecting the working state of the fan based on the
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`detected induced voltage.
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`DESCRIPTION
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`FIELD OF THE INVENTION
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`[0001] The present invention relates to a method and a device for controlling a permanent
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`magnet synchronous motor and an air conditioning device, in particular to a technology
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`for controlling a permanent magnet synchronous motor in a sine wave driving mode.
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`BACKGROUND OF THE INVENTION
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`[0002] A brushless DC motor serving as a permanent magnet synchronous motor is
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`provided with a stator winding and a rotor of a permanent magnet and is driven under the
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`control of an inverter and the like.
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`[0003] As known, these existing brushless DC motors are driven in a sine wave driving
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`mode in the absence of sensors for detecting revolving speeds and positions of rotors.
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`When a fan for heat exchange is driven, a part of three-phase alternating current is
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`supplied to the brushless DC motor by a three—phase PWM inverter, converted to a
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`revolving coordinate system of the rotor and used as flux current Id and torque current Iq.
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`The position and revolving speed (revolutions) of the rotor are calculated through these
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`currents, and drive control of the fan is performed on the basis of these calculated values.
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`[0004] However, under the condition that the position and revolving speed (revolutions)
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`of the rotor are calculated and drive control of the fan is performed on the basis of these
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`calculated values, the following unfavorable conditions exist, until the brushless DC
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`motor works at a speed of a certain degree, the working state of the fan still cannot be
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`learnt. Namely, the following problems exist: the working state of the fan cannot be learnt
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`during starting, and even if drive control is performed, the fan still cannot work or the fan
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`reverses.
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`[0005] Accordingly, the aim of the present invention is to provide a method and a device
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`for controlling a permanent magnet synchronous motor and an air conditioning device,
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`wherein in the absence of a sensor of a Hall IC and the like, the working state of the
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`permanent magnet synchronous motor during starting may be learnt, a rotor does not
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`reverse, then the working state of a fan during starting may be further learnt, and the fan
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`does not reverse.
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`[0006] For solving the problems, the invention provides a method for controlling a
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`permanent magnet synchronous motor, and for performing vector control on the
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`permanent magnet synchronous motor in a sine wave driving mode, characterized by
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`including: an induced voltage detecting process, used for detecting an induced voltage
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`generated in the permanent magnet synchronous motor; and a working state detecting
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`process, used for detecting the working state of the permanent magnet synchronous motor
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`based on the detected induced voltage.
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`{0007] Under such condition, the working state detecting process may also include a start
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`processing process, used for performing start processing to start the permanent magnet
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`synchronous motor under the condition that the permanent magnet synchronous motor is
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`stopped or is being stopped.
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`[0008] Moreover, the working state detecting process includes a revolution detecting
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`process for detecting revolutions of the permanent magnet synchronous motor, wherein
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`the condition that the permanent magnet synchronous motor is stopped or is being
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`stopped may be a condition that the detected revolutions are less than the stipulated
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`revolutions.
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`[0009] In addition, the working state detecting process includes: the revolution detecting
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`process, used for detecting revolutions of the permanent magnet synchronous motor;
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`when the detected revolutions are more than the stipulated revolutions, the working state
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`detecting process may also include a stop processing process, used for stopping revolving
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`of the permanent magnet synchronous motor; and a start processing process, used for
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`starting the permanent magnet synchronous motor which has stopped revolving in the
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`stop processing process.
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`[0010] Furthermore, the start processing process may also include: an initial position
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`transfer process, used for transferring a rotor to a stipulated angle range of a higher
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`acquiring probability of a positive torque enabling the rotor to rotate in a positive
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`revolving direction; and an initial drive control process, used for performing drive control
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`under the condition that the position of the rotor is within the stipulated angle range to
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`drive the rotor towards the positive revolving direction.
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`[0011] Moreover, a device for controlling a permanent magnet synchronous motor, and
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`for performing vector control on the permanent magnet synchronous motor in a sine
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`wave driving mode, characterized by including: an induced voltage detecting part, used
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`for detecting an induced voltage generated in the permanent magnet synchronous motor;
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`and a working state detecting part, used for detecting the working state of the permanent
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`magnet synchronous motor based on the detected induced voltage.
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`[0012] According to the structure, the induced voltage detecting part detects the induced
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`voltage generated in the permanent magnet synchronous motor.
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`[0013] Thus, the working state detecting part detects the working state of the permanent
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`magnet synchronous motor based on the induced voltage detected by the induced voltage
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`detecting part.
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`[0014] Under such condition, the working state detecting part may also include a start
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`processing part used for performing start processing to start the permanent magnet
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`synchronous motor when the permanent magnet synchronous motor is stopped or is being
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`stopped as detected.
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`[0015] Moreover, the working state detecting part includes a revolution detecting part
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`used for detecting revolutions of the permanent magnet synchronous motor, wherein the
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`condition that the permanent magnet synchronous motor is stopped or is being stopped
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`may be a condition that the detected revolutions are less than the stipulated revolutions.
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`[0016] In addition, the working state detecting part comprises the revolution detecting
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`part used for detecting the revolutions of the permanent magnet synchronous motor; the
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`controliing device comprises: a stop processing part, used enabling the permanent magnet
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`synchronous motor to stop revolving under the condition that the detected revolutions are
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`more than the stipulated revolutions; and a start processing part, used for starting the
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`permanent magnet synchronous motor which has stepped revolving through the stop
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`processing part.
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`[0017] Furthermore, the start processing part may also include: an initial position transfer
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`part, used for transferring a rotor to a stipulated angle range of a higher acquiring
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`probability of a positive torque enabling the rotor to rotate in a positive revolving
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`direction; and an initial drive control part, used for performing drive control under the
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`condition that the position of the rotor is within the stipulated angle range to drive the
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`rotor towards the positive revolving direction.
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`[0018] Moreover, an air conditioning device includes an indoor unit and an outdoor unit,
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`characterized by also including: a permanent magnet synchronous motor used for driving
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`a fan arranged in at least one of the indoor unit and the outdoor unit, an induced voltage
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`detecting part used for detecting an induced voltage generated in the permanent magnet
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`synchronous motor, and a working state detecting part used for detecting the working
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`state of the fan based on the detected induced voltage.
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`[0019] According to the structure, the induced voltage detecting part detects the induced
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`voltage generated in the permanent magnet synchronous motor for driving the fan.
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`{0020] Thus, the working state detecting part detects the working state of the fan.
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`BRIEF DESCRIPTION OF THE EMBODIMENTS
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`[0021] Next, optimal embodiments of the present invention are illustrated with reference
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`to accompanying drawings.
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`[0022] Fig. l is a diagram of a refrigerant circuit of an air conditioning device with a
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`compressor driven by a permanent magnet synchronous motor (called as brushless DC
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`motor below).
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`[0023] As shown in Fig. 1, the air conditioning device 10 includes an outdoor unit 11 and
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`an indoor unit 12. An outdoor refrigerant pipe 14 of the outdoor unit 11 is connected with
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`an indoor refrigerant pipe 15 of the indoor unit 12 through connecting pipes 24 and 25.
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`[0024] The outdoor unit 11 is arranged outdoors, and a compressor 16 is arranged on the
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`outdoor refrigerant pipe 14. The suction side of the compressor 16 is connected with an
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`accumulator 17. Moreover, the discharge side of the compressor 16 is connected with a
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`four-way valve 18 through the outdoor refrigerant pipe 14. The four-way valve 18 is
`connected with an outdoor heat exchanger 19 through the outdoor refrigerant pipe 14.
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`[0025] Moreover, an outdoor fan 20 which is driven by a brushless DC motor 30A and
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`blows air to the outdoor heat exchanger 19 is configured adjacent to the outdoor heat
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`exchanger 19.
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`[0026] On the other hand, the indoor unit 12 is arranged indoors, and an indoor heat
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`exchanger 21 is arranged on the indoor refrigerant pipe 15. In addition, an electric
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`expansion valve 22 is arranged nearby the indoor heat exchanger 21 in the indoor
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`refrigerant pipe 15 of the indoor unit 12. An indoor fan 23 which is driven by a brushless
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`DC motor 3013 and blows air to the indoor heat exchanger 21 is configured adjacent to
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`the indoor heat exchanger 21.
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`[0027] By switching the four-way valve 18 of the outdoor unit 11 to a refrigerating side
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`or a heating side, the air conditioning device 10 is set to refrigerate or heat. Namely,
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`when the four—way valve 18 is switched to the refrigerating side, a refrigerant flows along
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`the direction of solid arrows, the outdoor heat exchanger 19 serving as a condenser and
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`the indoor heat exchanger 21 serving as an evaporator are in a refrigerating state, and the
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`indoor heat exchanger 21 of the indoor unit 12 refrigerates indoors. Moreover, when the
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`four-way valve 18 is switched to the heating side, the refrigerant flows towards the
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`direction of dotted arrows, the indoor heat exchanger 21 serving as a condenser and the
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`outdoor heat exchanger 19 serving as an evaporator are in a heating state, and the indoor
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`heat exchanger 21 of the indoor unit 12 heats indoors.
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`10
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`[0028] Fig. 2 is a block diagram of a driving device for brushless DC motors.
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`[0029] Each of brushless DC motors 30A and 30B includes a stator winding and a rotor
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`of a permanent magnet which are not shown in the diagram, and these brushless DC
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`motors 30A and 3033 are driven by a brushless DC motor driving device 50 respectively.
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`In addition, the work of the brushless DC motor 30A is taken as a center for illustration
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`below.
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`[0030] The brushless DC motor driving device 50 roughly includes a three—phase PWM
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`inverter 31, an alternating current power supply 32, a rectifier circuit 33 and a control
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`device 34.
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`[0031] Direct current converted from alternating current of the alternating current power
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`supply 32 by the rectifier circuit 33 is supplied to the three-phase PWM inverter 31. Thus,
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`the three—phase PWM inverter 31 converts the direct current into alternating current
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`having the assigned frequency and voltage corresponding to the working state of the
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`brushless DC motor 30A, and the alternating current is supplied to the brushless DC
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`motor 30A, so as to control the revolving Speed and the like of the brushless DC motor
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`30A.
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`[0032] The
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`control device
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`34
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`roughly includes
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`a power
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`input part 35,
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`a
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`three—phase/two-phase coordinate conversion part 36, a rotor speed and position
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`calculating part 37, a speed control part 38, a phase control part 39, a current control part
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`40, a two—phase/threeuphase coordinate conversion part 41 and an induced voltage
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`detecting part 42.
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`[0033] The two-phase/three-phase coordinate conversion part 41 of the control device 34
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`outputs pulse—modulated sinusoidal voltage commands Vu, VV and Vw to a switching
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`element (not shown in the diagram) of the three-phase PWM inverter 31. Therefore, the
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`three—phase PWM inverter 31 supplies quasi—sinusoidai three-phase alternating current of
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`which the formation voltage is subjected to pulse width modulation (PWM) to the
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`brushless DC motor 30A.
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`[0034] The current input part 35 of the control device 34 performs A/D conversion
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`(analog to digital conversion) on two-phase alternating current 1,, and Iv in the three-phase
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`alternating current supplied to the brushless DC motor 30A by the three—phase PWM
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`inverter 31 and introduces the alternating current I1] and Iv. In this embodiment, subscripts
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`u, v and w correspond to phase u, phase v and phase w of the brushless DC motor 30A
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`respectively.
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`[0035] The three—phase/two-phase coordinate conversion part 36 converts the coordinates
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`of the alternating current L, and Iv introduced by the current input part 35 to a revolving
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`coordination system (d—q coordination system) on the rotor of the brushless DC motor
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`30A, and calculates flux current 1d (d-axis current) and torque currenth (q—axis current).
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`[0036] The rotor speed and position calculating part 37 calculates the position and
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`revolutions (speed) of the rotor in the brushless DC motor 30A based on the flux current
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`Id and torque current Icl converted by the threenphase/two-phase coordinate conversion
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`part 36 and the iike every lOOu, for example.
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`[0037] The speed control part 38 performs proportional integral control (PI control) based
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`on the deviation between the speed of the rotor calculated by the rotor speed and position
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`calculating part 37 and the target speed of the rotor every lms, for example, to generate a
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`torque current Iq target value.
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`[0038] The phase control part 39 identifies the state of a load by introducing the torque
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`currenth in direct proportion to the change of the load acting on the brushless DC motor
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`30A, to generate a flux current Id target value corresponding to the state of the load.
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`Specifically, by introducing the torque currenth in direct proportion to the increase of the
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`load acting on the brushless DC motor 30A, the flux current 13 target value is reduced on
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`the basis of the following formula. In addition, in the following formula, k is a positive
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`constant.
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`[0039] The flux current Id target value is equal to kxlqz. By reducing the flux current Id
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`target value, the flux voltage Vd output by the after-mentioned current control part 40 is
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`reduced,
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`the phases of the voltage commands Vu, VV and VW output by the
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`two—phase/threeuphase coordinate conversion part 41 are advanced, and the phases of the
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`voltage commands Vu, VV and VW delayed due to the increase of the load are restored.
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`[0040] The current control part 40 executes PI control based on the deviation between the
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`torque current Iq target value generated by the speed control part 38 and the actual torque
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`current lq to calculate a torque voltage VCl (Vq—axis voltage), and executes Pl control
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`based on the deviation between the flux current Id target value generated by the phase
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`control part 39 and the actual flux current 1d target value to calculate a flux voltage Vd
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`(Vd~axis voltage).
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`[0041] The two—phase/three-phase coordinate conversion part 41 converts the flux
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`voltage Vd and torque voltage Vq calculated by the current control part 40 to a
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`three—phase alternating current coordinate system to calculate the above—mentioned
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`pulse—modulated sinusoidal voltage commands Vu, Vv and Vw, these voltage commands
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`Vu, VV and Vw are output to the switching element (not shown in the diagram) of the
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`three—phase PWM inverter 31, and the quasi sinusoidal three—phase alternating current of
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`which the formation voltage is subjected to pulse width modulation is output from the
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`three-phase PWM inverter 31 to the brushless DC motor 30A (normal control).
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`[0042] The induced voltage detecting part 42 detects the induced voltages (Von, VGV and
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`VGW) generated through the revolving of the rotor of the brushless DC motor 30A.
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`[0043] Next, start control of the brushless DC motor driving device 50 is illustrated.
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`[0044] Firstly, the control device 34 of the brushless DC motor driving device 50 judges
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`whether a motor running command is formed or not based on the operation of an operator
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`or the preset program (step S l).
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`[0045] In judgment of step SI, if the motor running command is not formed (step S; No.
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`1), processing is transferred to main processing not shown in the diagram.
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`[0046] In judgment of step SI, if the motor running command is formed (step SI; Yes),
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`the induced voltage detecting part 42 detects the induced voltages (V311, VGV and VGW)
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`13
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`generated through the revolving of the rotor of the brushless motor 30A (step 32).
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`Moreover, the control device 34 detects the revolutions of the rotor of the brushless motor
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`30A based on the induced voltages. Namely, as shown in Fig. 5, the revolutions are
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`detected on the basis of the relation between the pro-stored induced voltages and the
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`revolutions.
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`[0047] Secondly, the control device 34 judges Whether the rotor of the brushless motor
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`30A is being stopped (or regarded in a state of being stopped) (step SB). The condition
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`that the rotor of the brushiess motor 30A is being stopped or regarded as in the state of
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`being stopped, as showa in Fig. 5,
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`is a condition that the detected induced voltage is
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`smaller than the stipulated induced voltage VG}.
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`[0048] In judgment of step S3, under the condition that the rotor of the brushless motor
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`30A is not stopped (step S3; No), Whether the revolutions of the rotor are bigger than the
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`stipulated revolutions X is judged, namely, as shown in Fig. 5, Whether the detected
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`induced voltage is bigger than the stipulated induced voltage Va; is judged (step S5).
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`[0049] In judgment of step S5, under the condition that the revolutions of the rotor are
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`bigger than the stipulated revolutions X, namely, the detected induced voltage is bigger
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`than the stipulated induced voltage Vgg, when the reversing of the rotor is judged through
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`rotor positioning processing of transferring the rotor to a stipulated position or through
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`detecting the phases of the induced voltages VG“, VGV and VGW, and motor stop
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`processing is performed through revolving control along the reverse direction (positive
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`revolving direction) and the like (step S6). Then, the processing is transferred to step S1
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`again for the same processing.
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`‘
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`[0050] In judgment of step SS, under the condition that the revolutions of the rotor are
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`smaller than the stipulated revolutions X, namely, the detected induced voltage is bigger
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`than the induced voltage VG1 and smaller than the induced voltage Vgg, the revolution is
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`temporary and stops after standby for a While, thus entering a standby state (step S7).
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`Then, the processing is transferred to step 81 again for the same processing.
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`14
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`[005]] In judgment of step S3, the rotor of the brushless motor 30A is being stopped or
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`regarded as in the state of being stopped, motor start processing is performed (step S4).
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`[0052] At this moment, the motor start processing is illustrated with reference to Fig. 5.
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`[0053] If the u phase direction of the motor is set to be 0r ], the rotor acquires a positive
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`torque in the revolving direction within the stipulated angle range (specifically
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`270[a ]~360[° D, and tends to revolve in the positive revolving direction.
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`[0054] The control device 34 performs rotor positioning processing enabling the rotor to
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`move to the stipulated position (nearby 300[D ] in this embodiment) (step 81 l).
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`[0055] Herein, the reason for setting the stipulated position of the rotor nearby the
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`stipulated angle (:3 00 [. ]) within the stipulated angle range is illustrated.
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`[0056] Substantially, the position of the rotor is preferably transferred to the stipulated
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`angle range of a higher acquiring probability of the positive torque enabling the
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`above-mentioned rotor to rotate in the positive revolving direction when the brushless DC
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`motor 30A (permanent magnet synchronous motor) is started.
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`[0057] The stipulated angle range, preferably, will be supplied to the reduction range of
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`the flux current and the increase range of the torque current under the condition that the
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`three-phase alternating current of the brushless DC motor 30A is converted to the
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`revolving coordinate system of the rotor. Furthermore, more preferably, the angle nearby
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`the center angle within the stipulated angie range, namely the stipulated angle where the
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`increase rate of the above-mentioned torque current is large compared with the center
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`angle, is set to be a target rotor position.
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`[0058] As the angle range satisfying these conditions, the relation between the torque and
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`the position of the rotor of Fig. 4 is actually measured, as a result, under the condition of
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`this embodiment, the stipulated angle range is 270[° ]~360[° ]. In addition, the center
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`angle Within the stipulated angle range is 315[D ], and the angle nearby the center angle,
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`namely the stipulated angle where the increase rate of the torque current
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`is large
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`compared with the center angle (315[° D, is actually solved, thus obtaining an optimal
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`15
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`result of the target rotor position nearby 300[° ].
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`[0059] In addition, the target rotor position is changed according to the structure of the
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`brushless DC motor 30A, and needs to be appropriately determined on the basis of the
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`structure of the actually used brushless DC motor 30A.
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`[0060] Thirdly, the control device 34 judges Whether the stipulated time that the rotor
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`probably has moved to the stipulated position after rotor positioning processing has
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`arrived or not (step 812).
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`[0061] In judgment of step 812, under the condition that the stipulated time does not
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`arrive (step 812; No), the rotor positioning processing is continued (step 811).
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`[0062] In the judging process of step 312, under the condition that the stipulated time has
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`arrived, the control device 34 sets the flux current to be 0. In order to monotonically
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`increase the torque current Iq, the current control part 40 sets the voltage Vd to be 0[V], so
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`that the voltage Vq is monotonically increased and the torque is slowly increased. At this
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`moment, the calculated revolving speed (current speed) output by the rotor speed and
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`position calculating part 37 is not considered.
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`[0063] Namely, the current control part 40 generates the voltage Vq corresponding to the
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`target value of the stipulated torque current Iq based on the stipulated expression of first
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`degree and according to the mode of monotonically increasing the voltage. In addition, if
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`the voltage is continuously and monotonically increased, an over—current state is formed
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`soon, so the monotonic increase period is limited within the stipulated period.
`
`[0064] Then the control device 34 judges whether the rotor positively revolves (step
`
`814).
`
`[0065] In judgment of step 814, under the condition that the rotor does not positively
`
`revolve (step 814; No), processing of stopping the operation of the brushless DC motor
`
`30A is performed (step 820), the rotor positioning processing (step S 11) is executed again
`
`under the condition that the operation of the brushless DC motor 30A is completely
`
`stopped), and the same processing is repeated below.
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`16
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`

`

`[0066] In judgment of step 814, if the rotor positively revolves (step SM; Yes), Whether
`
`the preset stipulated time (3 seconds in the above—mentioned example) has arrived after
`
`the voltage Vq is monotonically increased is judged (step SIS).
`
`[0067] In judgment of step S15, under the condition that the stipulated time does not
`
`arrived after the voltage Vq is monotonically increased (step S15; No), the processing is
`
`transferred to step 813 again, and the voltage Vq is continuously and monotonically
`
`increased.
`
`[0068] In judgment of step SIS, under the condition that the stipulated time has arrived
`
`after the voltage Vq is monotonically increased (step SIS; Yes), the above—mentioned
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`normal control is performed (step 816).
`
`[0069] Finally, the control device 34 judges whether the rotor positively revolves (step
`
`817)
`
`[0070] In judgment of step SI7, under the condition that the rotor does not positively
`
`revolve (step 817; No), processing of stopping the operation of the brushless DC motor
`30A is performed (step S20), the rotor positioning processing (step 811) is executed again
`
`under the condition that the operation of the brushless DC motor 30A is completely
`
`stopped), and the same processing is repeated below.
`
`[0071] On the other hand, in judgment of step 817, under the condition that the rotor
`
`positively revolves (step 817; Yes), the control device 34 judges Whether an operator or
`
`an abnormity detection sensor sends out a processing stop command (step SIS).
`
`[0072] In judgment of step SIS, under the condition that the operator or the abnormity
`
`detection sensor does not send out the command for stopping processing (step S18; No),
`
`the processing is transferred to step 816 again, and the same processing is repeated
`
`below.
`
`[0073] In judgment of step SIS, under the condition that the operator or the abnormity
`
`detection sensor sends out
`
`the command for stopping processing (step SIS; Yes),
`
`operation stop processing for stopping the operation of the brushless DC motor 30A is
`
`17
`
`

`

`performed (step 820), and processing is ended.
`
`[0074] As illustrated above, according to this embodiment, the working state (revolving
`
`direction, revolving speed and the like) of the brushless DC motor 30A during starting
`
`may be learnt, and the most appropriate start control may be performed through the
`
`control corresponding to the working state to reliably start the brushless DC motor 30A.
`
`Further, the fan 20 or the fan 23 may be reliably started.
`
`{0075] In the illustration above, the start of the fan of the air conditioning device 10 is
`
`illustrated, and in other equipment, the illustration is also applicable when the working
`
`state of the permanent magnet synchronous motor or a driven body driven by the
`
`permanent magnet synchronous motor is detected.
`
`[0076] In the illustration above, the working state of the brushless DC motor is detected
`
`by detecting the induced voltage of the brushless DC motor, or, the induced voltage of the
`
`brushless DC motor is converted into current through a voltage/current conversion circuit
`
`of a resistor element and the like, and then the working state of the brushless DC motor is
`
`detected on the basis of the current.
`
`[0077] According to the present invention, the working state of the permanent magnet
`
`synchronous motor during starting may be learnt without the sensor such as the Halt IC,
`
`then the working state of the driven body (such as the fan, gear, pulley, crank and the like)
`
`driven by the permanent magnet synchronous motor may be learnt, and start control may
`
`be reliably performed.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
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`Fig. l is a diagram of a refrigerant circuit of an air conditioning device wi